The most powerful tool you have to change your brain and your health is your fork. Food is not just calories or energy. Food contains information that talks to your genes, turning them on or off and affecting their function moment to moment.

Food is the fastest acting and most powerful medicine you can take to change your life. We call this nutrigenomics. Think of your genes as the software that runs everything in your body. Just like your computer software, your genes only do what you instruct them to do with the stroke of your keyboard.

The foods you eat are the keystrokes that send messages to your genes telling them what to do—creating health or disease.

Imagine what messages you are sending with a double cheeseburger, large fries and a 48-ounce cola. Then consider what messages you might send instead with deep red wild salmon, braised greens and brown rice.

The science of nutrigenomics allows us to personalize medicine. Not everyone with the same problems needs the same prescription. Your individual genetic makeup determines what you need to be optimally healthy.

Consider that you only have about 30,000 genes, but those genes contain about 3 million tiny variations called single nucleotide polymorphisms (SNPs) that make up who you are. These variations make your individual needs slightly different from my individual needs.

Put another way, we all have different needs for food, vitamins, rest, exercise, stress tolerance or ability to handle toxins.

The key, then, becomes personalizing a program based on your strengths and vulnerabilities—your individual needs. By analyzing where you are out of balance and then applying the science of nutrigenomics to help reestablish balance, you can design a treatment matched to your individual needs.

Personalization, Simplified

Personalizing doesn’t have to be complicated. The first step is to take out the bad stuff, or the things that create imbalance. Those imbalances include a nutrient-poor, processed diet, toxins, allergens, infections and stress.

Think of it this way. If you have 10 tacks in your foot, you can’t take out one, pop an aspirin and hope to feel better. You need to find and take out all the tacks; taking out just one of them won’t make you better.

The second step is to add the good stuff, including high-quality whole foods, nutrients, water, oxygen, light, movement, sleep, relaxation, community, connection, love, meaning and purpose. When you add those good things, the body’s natural intelligence and healing system will take care of the rest.

Using this simple yet comprehensive method—removing the bad things and replacing them with good things—allows me to treat virtually all diseases, whether they are “in the brain” or “in the body.” This strategy works for one simple reason: the body and the brain are one system.

Upgrade Your Genes; Downsize Your Jeans

Allow me to explain how I use nutrigenomics to reverse diabesity, the continuum of abnormal biology that ranges from mild insulin resistance to full-blown diabetes.

As I mentioned before, food is information. If you want to turn off the genes that lead to diabesity and turn on the genes that lead to health, the key becomes the quality and type of food you eat, not necessarily the number of calories you consume or the ratio of protein to fat to carbohydrate in your diet. You need to put your genes on a diet.

As David Ludwig, one of the leading obesity researchers at Harvard Medical School, said, “Molecular pathways involved in hormone action [like insulin resistance]have been the target of a multibillion-dollar pharmaceutical research effort. However, many of these pathways may normally be under dietary regulation. The results of the present study [on nutrigenomics]emphasize the age-old wisdom to ‘use food as medicine’—in this case, for the targeted prevention and treatment of obesity, diabetes and heart disease.”

Shifting from a nutrient-poor diet to a nutrient-rich diet abundant in plant foods such as fruits, vegetables, nuts, seeds, beans and whole grains improves the expression of hundreds of genes that control insulin function and obesity.

To use just one example, the vast array of colors in vegetables represents over 25,000 beneficial chemicals.

Our hunter-gatherer ancestors ate over 800 varieties of plant foods. Today, we don’t even consume a fraction of that amount. We need to make an extra effort to eat many different foods to get the full range of benefits. Remember: eat the rainbow!

An optimal diet to prevent and treat diabesity also includes healthy fats such as olive oil, nuts, avocados, and omega-3 fats, along with modest amounts of lean animal protein. This is commonly known as a Mediterranean diet. It is a diet of whole, real, fresh food that has been prepared in a kitchen, not a factory.

This way of eating has been shown to prevent and even reverse diabesity. It has broad-ranging benefits for our health, and beneficially affects our entire physiology, reducing inflammation, boosting detoxification, balancing hormones and providing powerful antioxidant protection—all things that fix the underlying causes of disease.

Even with a perfect diet, the combination of our depleted soils, the storage and transportation of our food, genetic alterations of traditional heirloom species, and the increased stress and nutritional demands resulting from a toxic environment make it impossible for us to get the vitamins and minerals we need solely from the foods we eat. The evidence shows that we cannot get away from the need for nutritional supplements.

That’s why you need a full complement of vitamins and minerals, and you may need to individually correct specific deficiencies, including deficiencies in chromium, biotin, vitamin D, magnesium, zinc, alpha lipoic acid, and omega-3 fats.

You can find all these nutrients in individual supplements, but I recommend a blood sugar-balancing formulation as well as fish oil soft gels to simplify your nutrient intake.

Fiber is a great blood sugar stabilizer to reverse diabesity, but unfortunately most of us do not eat enough high-fiber plant foods. That’s why I also recommend glucomannan, a soluble fiber derived from an Asian potato-like tuber.

Also called Konjac fiber, glucomannan is much more viscous than usual fibers, retaining up to 17 times its weight in water. Expanding in the stomach, small and large intestine, it absorbs fat, accelerates elimination, reduces cholesterol, blunts sugar absorption and facilitates weight loss, in part by increasing feelings of satiety.

Combine these foods and nutrients with quality sleep, controlling stress, and finding joy and meaning in life, and you have the perfect formula to stay lean, happy and healthy.

Nine Ways to Make Your Grocery Store a “Farmacy”

I hope I have demonstrated that what you put at the end of your fork is a more powerful medicine than anything you will find at the bottom of a pill bottle. Food is the most powerful medicine available to heal chronic disease, which will account for over 50 million deaths and cost the global economy $47 trillion by 2030. That’s why we must change our perspective about food.

All you need to do is eat your medicine and think of your grocery store as your pharmacy. Here are nine ways to do that:

1. Skip the labels: Whenever possible, do not buy foods with labels. Avoid foods in a box, package or can.

2. Keep it simple: If the food does have a label, it should have fewer than five ingredients. Beware of food with “health claims” on the label. Cola is “fat free.” That doesn’t make it healthy.

3. Steer clear of the white menaces: Stay away from white sugar and white flour, which acts like sugar in your body. Learn the numerous disguises for sugar and get rid of any food that contains them.

4. Dump this lethal sugar: Throw out any food with high fructose corn syrup (HFCS) on the label. You already know it is not good for you, but just in case you need reminding, read this blog for the five reasons HFCS will kill you.

5. Avoid this bad fat: Eliminate any food with the word “hydrogenated” on the label, which translates into trans fats.

9. Ditch artificial sweeteners: Remember that food is information, not just calories. Diet sodas and other foods and drinks with artificial sweeteners are almost always calorie free, but they will still make you fat.

When in Doubt, Stick with this One Rule

If it came from the earth or a farmer’s field and not a food chemist’s lab, then it is safe to eat. Like Michael Pollan, author of Food Rules, says, “If it came from a plant, eat it; if it was made in a plant, don’t.” It is really that simple.

About the author:Mark Hyman, MD, believes that we all deserve a life of vitality—and that we have the potential to create it for ourselves. That’s why he is dedicated to tackling the root causes of chronic disease by harnessing the power of Functional Medicine to transform healthcare. He is a practicing family physician, an nine-time #1 New York Times bestselling author, and an internationally recognized leader, speaker, educator, and advocate in his field. He is the Director of the Cleveland Clinic Center for Functional Medicine. He is also the founder and medical director of The UltraWellness Center, chairman of the board of the Institute for Functional Medicine, a medical editor of The Huffington Post, and has been a regular medical contributor on many television shows including CBS This Morning, the Today Show, CNN, The View, the Katie Couric show and The Dr. Oz Show.